src/emitter.c

   1
   2 #include "yaml_private.h"
   3
   4 /*
   5  * Flush the buffer if needed.
   6  */
   7
   8 #define FLUSH(emitter)                                                          \
   9     ((emitter->buffer.pointer+5 < emitter->buffer.end)                          \
  10      || yaml_emitter_flush(emitter))
  11
  12 /*
  13  * Put a character to the output buffer.
  14  */
  15
  16 #define PUT(emitter,value)                                                      \
  17     (FLUSH(emitter)                                                             \
  18      && (*(emitter->buffer.pointer++) = (yaml_char_t)(value),                   \
  19          emitter->column ++,                                                    \
  20          1))
  21
  22 /*
  23  * Put a line break to the output buffer.
  24  */
  25
  26 #define PUT_BREAK(emitter)                                                      \
  27     (FLUSH(emitter)                                                             \
  28      && ((emitter->line_break == YAML_CR_BREAK ?                                \
  29              (*(emitter->buffer.pointer++) = (yaml_char_t) '\r') :              \
  30           emitter->line_break == YAML_LN_BREAK ?                                \
  31              (*(emitter->buffer.pointer++) = (yaml_char_t) '\n') :              \
  32           emitter->line_break == YAML_CRLN_BREAK ?                              \
  33              (*(emitter->buffer.pointer++) = (yaml_char_t) '\r',                \
  34               *(emitter->buffer.pointer++) = (yaml_char_t) '\n') : 0),          \
  35          emitter->column = 0,                                                   \
  36          emitter->line ++,                                                      \
  37          1))
  38
  39 /*
  40  * Copy a character from a string into buffer.
  41  */
  42
  43 #define WRITE(emitter,string)                                                   \
  44     (FLUSH(emitter)                                                             \
  45      && (COPY(emitter->buffer,string),                                          \
  46          emitter->column ++,                                                    \
  47          1))
  48
  49 /*
  50  * Copy a line break character from a string into buffer.
  51  */
  52
  53 #define WRITE_BREAK(emitter,string)                                             \
  54     (FLUSH(emitter)                                                             \
  55      && (CHECK(string,'\n') ?                                                   \
  56          (PUT_BREAK(emitter),                                                   \
  57           string.pointer ++,                                                    \
  58           1) :                                                                  \
  59          (COPY(emitter->buffer,string),                                         \
  60           emitter->column = 0,                                                  \
  61           emitter->line ++,                                                     \
  62           1)))
  63
  64 /*
  65  * API functions.
  66  */
  67
  68 YAML_DECLARE(int)
  69 yaml_emitter_emit(yaml_emitter_t *emitter, yaml_event_t *event);
  70
  71 /*
  72  * Utility functions.
  73  */
  74
  75 static int
  76 yaml_emitter_set_emitter_error(yaml_emitter_t *emitter, const char *problem);
  77
  78 static int
  79 yaml_emitter_need_more_events(yaml_emitter_t *emitter);
  80
  81 static int
  82 yaml_emitter_append_tag_directive(yaml_emitter_t *emitter,
  83         yaml_tag_directive_t value, int allow_duplicates);
  84
  85 static int
  86 yaml_emitter_increase_indent(yaml_emitter_t *emitter,
  87         int flow, int indentless);
  88
  89 /*
  90  * State functions.
  91  */
  92
  93 static int
  94 yaml_emitter_state_machine(yaml_emitter_t *emitter, yaml_event_t *event);
  95
  96 static int
  97 yaml_emitter_emit_stream_start(yaml_emitter_t *emitter,
  98         yaml_event_t *event);
  99
 100 static int
 101 yaml_emitter_emit_document_start(yaml_emitter_t *emitter,
 102         yaml_event_t *event, int first);
 103
 104 static int
 105 yaml_emitter_emit_document_content(yaml_emitter_t *emitter,
 106         yaml_event_t *event);
 107
 108 static int
 109 yaml_emitter_emit_document_end(yaml_emitter_t *emitter,
 110         yaml_event_t *event);
 111
 112 static int
 113 yaml_emitter_emit_flow_sequence_item(yaml_emitter_t *emitter,
 114         yaml_event_t *event, int first);
 115
 116 static int
 117 yaml_emitter_emit_flow_mapping_key(yaml_emitter_t *emitter,
 118         yaml_event_t *event, int first);
 119
 120 static int
 121 yaml_emitter_emit_flow_mapping_value(yaml_emitter_t *emitter,
 122         yaml_event_t *event, int simple);
 123
 124 static int
 125 yaml_emitter_emit_block_sequence_item(yaml_emitter_t *emitter,
 126         yaml_event_t *event, int first);
 127
 128 static int
 129 yaml_emitter_emit_block_mapping_key(yaml_emitter_t *emitter,
 130         yaml_event_t *event, int first);
 131
 132 static int
 133 yaml_emitter_emit_block_mapping_value(yaml_emitter_t *emitter,
 134         yaml_event_t *event, int simple);
 135
 136 static int
 137 yaml_emitter_emit_node(yaml_emitter_t *emitter, yaml_event_t *event,
 138         int root, int sequence, int mapping, int simple_key);
 139
 140 static int
 141 yaml_emitter_emit_alias(yaml_emitter_t *emitter, yaml_event_t *event);
 142
 143 static int
 144 yaml_emitter_emit_scalar(yaml_emitter_t *emitter, yaml_event_t *event);
 145
 146 static int
 147 yaml_emitter_emit_sequence_start(yaml_emitter_t *emitter, yaml_event_t *event);
 148
 149 static int
 150 yaml_emitter_emit_mapping_start(yaml_emitter_t *emitter, yaml_event_t *event);
 151
 152 /*
 153  * Checkers.
 154  */
 155
 156 static int
 157 yaml_emitter_check_empty_document(yaml_emitter_t *emitter);
 158
 159 static int
 160 yaml_emitter_check_empty_sequence(yaml_emitter_t *emitter);
 161
 162 static int
 163 yaml_emitter_check_empty_mapping(yaml_emitter_t *emitter);
 164
 165 static int
 166 yaml_emitter_check_simple_key(yaml_emitter_t *emitter);
 167
 168 static int
 169 yaml_emitter_select_scalar_style(yaml_emitter_t *emitter, yaml_event_t *event);
 170
 171 /*
 172  * Processors.
 173  */
 174
 175 static int
 176 yaml_emitter_process_anchor(yaml_emitter_t *emitter);
 177
 178 static int
 179 yaml_emitter_process_tag(yaml_emitter_t *emitter);
 180
 181 static int
 182 yaml_emitter_process_scalar(yaml_emitter_t *emitter);
 183
 184 /*
 185  * Analyzers.
 186  */
 187
 188 static int
 189 yaml_emitter_analyze_version_directive(yaml_emitter_t *emitter,
 190         yaml_version_directive_t version_directive);
 191
 192 static int
 193 yaml_emitter_analyze_tag_directive(yaml_emitter_t *emitter,
 194         yaml_tag_directive_t tag_directive);
 195
 196 static int
 197 yaml_emitter_analyze_anchor(yaml_emitter_t *emitter,
 198         yaml_char_t *anchor, int alias);
 199
 200 static int
 201 yaml_emitter_analyze_tag(yaml_emitter_t *emitter,
 202         yaml_char_t *tag);
 203
 204 static int
 205 yaml_emitter_analyze_scalar(yaml_emitter_t *emitter,
 206         yaml_char_t *value, size_t length);
 207
 208 static int
 209 yaml_emitter_analyze_event(yaml_emitter_t *emitter,
 210         yaml_event_t *event);
 211
 212 /*
 213  * Writers.
 214  */
 215
 216 static int
 217 yaml_emitter_write_bom(yaml_emitter_t *emitter);
 218
 219 static int
 220 yaml_emitter_write_indent(yaml_emitter_t *emitter);
 221
 222 static int
 223 yaml_emitter_write_indicator(yaml_emitter_t *emitter,
 224         char *indicator, int need_whitespace,
 225         int is_whitespace, int is_indention);
 226
 227 static int
 228 yaml_emitter_write_anchor(yaml_emitter_t *emitter,
 229         yaml_char_t *value, size_t length);
 230
 231 static int
 232 yaml_emitter_write_tag_handle(yaml_emitter_t *emitter,
 233         yaml_char_t *value, size_t length);
 234
 235 static int
 236 yaml_emitter_write_tag_content(yaml_emitter_t *emitter,
 237         yaml_char_t *value, size_t length, int need_whitespace);
 238
 239 static int
 240 yaml_emitter_write_plain_scalar(yaml_emitter_t *emitter,
 241         yaml_char_t *value, size_t length, int allow_breaks);
 242
 243 static int
 244 yaml_emitter_write_single_quoted_scalar(yaml_emitter_t *emitter,
 245         yaml_char_t *value, size_t length, int allow_breaks);
 246
 247 static int
 248 yaml_emitter_write_double_quoted_scalar(yaml_emitter_t *emitter,
 249         yaml_char_t *value, size_t length, int allow_breaks);
 250
 251 static int
 252 yaml_emitter_determine_chomping(yaml_emitter_t *emitter,
 253         yaml_string_t string);
 254
 255 static int
 256 yaml_emitter_write_literal_scalar(yaml_emitter_t *emitter,
 257         yaml_char_t *value, size_t length);
 258
 259 static int
 260 yaml_emitter_write_folded_scalar(yaml_emitter_t *emitter,
 261         yaml_char_t *value, size_t length);
 262
 263 /*
 264  * Set an emitter error and return 0.
 265  */
 266
 267 static int
 268 yaml_emitter_set_emitter_error(yaml_emitter_t *emitter, const char *problem)
 269 {
 270     emitter->error = YAML_EMITTER_ERROR;
 271     emitter->problem = problem;
 272
 273     return 0;
 274 }
 275
 276 /*
 277  * Emit an event.
 278  */
 279
 280 YAML_DECLARE(int)
 281 yaml_emitter_emit(yaml_emitter_t *emitter, yaml_event_t *event)
 282 {
 283     if (!ENQUEUE(emitter, emitter->events, *event)) {
 284         yaml_event_delete(event);
 285         return 0;
 286     }
 287
 288     while (!yaml_emitter_need_more_events(emitter)) {
 289         if (!yaml_emitter_analyze_event(emitter, emitter->events.head))
 290             return 0;
 291         if (!yaml_emitter_state_machine(emitter, emitter->events.head))
 292             return 0;
 293         yaml_event_delete(&DEQUEUE(emitter, emitter->events));
 294     }
 295
 296     return 1;
 297 }
 298
 299 /*
 300  * Check if we need to accumulate more events before emitting.
 301  *
 302  * We accumulate extra
 303  *  - 1 event for DOCUMENT-START
 304  *  - 2 events for SEQUENCE-START
 305  *  - 3 events for MAPPING-START
 306  */
 307
 308 static int
 309 yaml_emitter_need_more_events(yaml_emitter_t *emitter)
 310 {
 311     int level = 0;
 312     int accumulate = 0;
 313     yaml_event_t *event;
 314
 315     if (QUEUE_EMPTY(emitter, emitter->events))
 316         return 1;
 317
 318     switch (emitter->events.head->type) {
 319         case YAML_DOCUMENT_START_EVENT:
 320             accumulate = 1;
 321             break;
 322         case YAML_SEQUENCE_START_EVENT:
 323             accumulate = 2;
 324             break;
 325         case YAML_MAPPING_START_EVENT:
 326             accumulate = 3;
 327             break;
 328         default:
 329             return 0;
 330     }
 331
 332     if (emitter->events.tail - emitter->events.head > accumulate)
 333         return 0;
 334
 335     for (event = emitter->events.head; event != emitter->events.tail; event ++) {
 336         switch (event->type) {
 337             case YAML_STREAM_START_EVENT:
 338             case YAML_DOCUMENT_START_EVENT:
 339             case YAML_SEQUENCE_START_EVENT:
 340             case YAML_MAPPING_START_EVENT:
 341                 level += 1;
 342                 break;
 343             case YAML_STREAM_END_EVENT:
 344             case YAML_DOCUMENT_END_EVENT:
 345             case YAML_SEQUENCE_END_EVENT:
 346             case YAML_MAPPING_END_EVENT:
 347                 level -= 1;
 348                 break;
 349             default:
 350                 break;
 351         }
 352         if (!level)
 353             return 0;
 354     }
 355
 356     return 1;
 357 }
 358
 359 /*
 360  * Append a directive to the directives stack.
 361  */
 362
 363 static int
 364 yaml_emitter_append_tag_directive(yaml_emitter_t *emitter,
 365         yaml_tag_directive_t value, int allow_duplicates)
 366 {
 367     yaml_tag_directive_t *tag_directive;
 368     yaml_tag_directive_t copy = { NULL, NULL };
 369
 370     for (tag_directive = emitter->tag_directives.start;
 371             tag_directive != emitter->tag_directives.top; tag_directive ++) {
 372         if (strcmp((char *)value.handle, (char *)tag_directive->handle) == 0) {
 373             if (allow_duplicates)
 374                 return 1;
 375             return yaml_emitter_set_emitter_error(emitter,
 376                     "duplicate %TAG directive");
 377         }
 378     }
 379
 380     copy.handle = yaml_strdup(value.handle);
 381     copy.prefix = yaml_strdup(value.prefix);
 382     if (!copy.handle || !copy.prefix) {
 383         emitter->error = YAML_MEMORY_ERROR;
 384         goto error;
 385     }
 386
 387     if (!PUSH(emitter, emitter->tag_directives, copy))
 388         goto error;
 389
 390     return 1;
 391
 392 error:
 393     yaml_free(copy.handle);
 394     yaml_free(copy.prefix);
 395     return 0;
 396 }
 397
 398 /*
 399  * Increase the indentation level.
 400  */
 401
 402 static int
 403 yaml_emitter_increase_indent(yaml_emitter_t *emitter,
 404         int flow, int indentless)
 405 {
 406     if (!PUSH(emitter, emitter->indents, emitter->indent))
 407         return 0;
 408
 409     if (emitter->indent < 0) {
 410         emitter->indent = flow ? emitter->best_indent : 0;
 411     }
 412     else if (!indentless) {
 413         emitter->indent += emitter->best_indent;
 414     }
 415
 416     return 1;
 417 }
 418
 419 /*
 420  * State dispatcher.
 421  */
 422
 423 static int
 424 yaml_emitter_state_machine(yaml_emitter_t *emitter, yaml_event_t *event)
 425 {
 426     switch (emitter->state)
 427     {
 428         case YAML_EMIT_STREAM_START_STATE:
 429             return yaml_emitter_emit_stream_start(emitter, event);
 430
 431         case YAML_EMIT_FIRST_DOCUMENT_START_STATE:
 432             return yaml_emitter_emit_document_start(emitter, event, 1);
 433
 434         case YAML_EMIT_DOCUMENT_START_STATE:
 435             return yaml_emitter_emit_document_start(emitter, event, 0);
 436
 437         case YAML_EMIT_DOCUMENT_CONTENT_STATE:
 438             return yaml_emitter_emit_document_content(emitter, event);
 439
 440         case YAML_EMIT_DOCUMENT_END_STATE:
 441             return yaml_emitter_emit_document_end(emitter, event);
 442
 443         case YAML_EMIT_FLOW_SEQUENCE_FIRST_ITEM_STATE:
 444             return yaml_emitter_emit_flow_sequence_item(emitter, event, 1);
 445
 446         case YAML_EMIT_FLOW_SEQUENCE_ITEM_STATE:
 447             return yaml_emitter_emit_flow_sequence_item(emitter, event, 0);
 448
 449         case YAML_EMIT_FLOW_MAPPING_FIRST_KEY_STATE:
 450             return yaml_emitter_emit_flow_mapping_key(emitter, event, 1);
 451
 452         case YAML_EMIT_FLOW_MAPPING_KEY_STATE:
 453             return yaml_emitter_emit_flow_mapping_key(emitter, event, 0);
 454
 455         case YAML_EMIT_FLOW_MAPPING_SIMPLE_VALUE_STATE:
 456             return yaml_emitter_emit_flow_mapping_value(emitter, event, 1);
 457
 458         case YAML_EMIT_FLOW_MAPPING_VALUE_STATE:
 459             return yaml_emitter_emit_flow_mapping_value(emitter, event, 0);
 460
 461         case YAML_EMIT_BLOCK_SEQUENCE_FIRST_ITEM_STATE:
 462             return yaml_emitter_emit_block_sequence_item(emitter, event, 1);
 463
 464         case YAML_EMIT_BLOCK_SEQUENCE_ITEM_STATE:
 465             return yaml_emitter_emit_block_sequence_item(emitter, event, 0);
 466
 467         case YAML_EMIT_BLOCK_MAPPING_FIRST_KEY_STATE:
 468             return yaml_emitter_emit_block_mapping_key(emitter, event, 1);
 469
 470         case YAML_EMIT_BLOCK_MAPPING_KEY_STATE:
 471             return yaml_emitter_emit_block_mapping_key(emitter, event, 0);
 472
 473         case YAML_EMIT_BLOCK_MAPPING_SIMPLE_VALUE_STATE:
 474             return yaml_emitter_emit_block_mapping_value(emitter, event, 1);
 475
 476         case YAML_EMIT_BLOCK_MAPPING_VALUE_STATE:
 477             return yaml_emitter_emit_block_mapping_value(emitter, event, 0);
 478
 479         case YAML_EMIT_END_STATE:
 480             return yaml_emitter_set_emitter_error(emitter,
 481                     "expected nothing after STREAM-END");
 482
 483         default:
 484             assert(1);      /* Invalid state. */
 485     }
 486
 487     return 0;
 488 }
 489
 490 /*
 491  * Expect STREAM-START.
 492  */
 493
 494 static int
 495 yaml_emitter_emit_stream_start(yaml_emitter_t *emitter,
 496         yaml_event_t *event)
 497 {
 498     if (event->type == YAML_STREAM_START_EVENT)
 499     {
 500         if (!emitter->encoding) {
 501             emitter->encoding = event->data.stream_start.encoding;
 502         }
 503
 504         if (!emitter->encoding) {
 505             emitter->encoding = YAML_UTF8_ENCODING;
 506         }
 507
 508         if (emitter->best_indent < 2 || emitter->best_indent > 9) {
 509             emitter->best_indent  = 2;
 510         }
 511
 512         if (emitter->best_width >= 0
 513                 && emitter->best_width <= emitter->best_indent*2) {
 514             emitter->best_width = 80;
 515         }
 516
 517         if (emitter->best_width < 0) {
 518             emitter->best_width = INT_MAX;
 519         }
 520
 521         if (!emitter->line_break) {
 522             emitter->line_break = YAML_LN_BREAK;
 523         }
 524
 525         emitter->indent = -1;
 526
 527         emitter->line = 0;
 528         emitter->column = 0;
 529         emitter->whitespace = 1;
 530         emitter->indention = 1;
 531
 532         if (emitter->encoding != YAML_UTF8_ENCODING) {
 533             if (!yaml_emitter_write_bom(emitter))
 534                 return 0;
 535         }
 536
 537         emitter->state = YAML_EMIT_FIRST_DOCUMENT_START_STATE;
 538
 539         return 1;
 540     }
 541
 542     return yaml_emitter_set_emitter_error(emitter,
 543             "expected STREAM-START");
 544 }
 545
 546 /*
 547  * Expect DOCUMENT-START or STREAM-END.
 548  */
 549
 550 static int
 551 yaml_emitter_emit_document_start(yaml_emitter_t *emitter,
 552         yaml_event_t *event, int first)
 553 {
 554     if (event->type == YAML_DOCUMENT_START_EVENT)
 555     {
 556         yaml_tag_directive_t default_tag_directives[] = {
 557             {(yaml_char_t *)"!", (yaml_char_t *)"!"},
 558             {(yaml_char_t *)"!!", (yaml_char_t *)"tag:yaml.org,2002:"},
 559             {NULL, NULL}
 560         };
 561         yaml_tag_directive_t *tag_directive;
 562         int implicit;
 563
 564         if (event->data.document_start.version_directive) {
 565             if (!yaml_emitter_analyze_version_directive(emitter,
 566                         *event->data.document_start.version_directive))
 567                 return 0;
 568         }
 569
 570         for (tag_directive = event->data.document_start.tag_directives.start;
 571                 tag_directive != event->data.document_start.tag_directives.end;
 572                 tag_directive ++) {
 573             if (!yaml_emitter_analyze_tag_directive(emitter, *tag_directive))
 574                 return 0;
 575             if (!yaml_emitter_append_tag_directive(emitter, *tag_directive, 0))
 576                 return 0;
 577         }
 578
 579         for (tag_directive = default_tag_directives;
 580                 tag_directive->handle; tag_directive ++) {
 581             if (!yaml_emitter_append_tag_directive(emitter, *tag_directive, 1))
 582                 return 0;
 583         }
 584
 585         implicit = event->data.document_start.implicit;
 586         if (!first || emitter->canonical) {
 587             implicit = 0;
 588         }
 589
 590         if (event->data.document_start.version_directive) {
 591             implicit = 0;
 592             if (!yaml_emitter_write_indicator(emitter, "%YAML", 1, 0, 0))
 593                 return 0;
 594             if (!yaml_emitter_write_indicator(emitter, "1.1", 1, 0, 0))
 595                 return 0;
 596             if (!yaml_emitter_write_indent(emitter))
 597                 return 0;
 598         }
 599
 600         if (event->data.document_start.tag_directives.start
 601                 != event->data.document_start.tag_directives.end) {
 602             implicit = 0;
 603             for (tag_directive = event->data.document_start.tag_directives.start;
 604                     tag_directive != event->data.document_start.tag_directives.end;
 605                     tag_directive ++) {
 606                 if (!yaml_emitter_write_indicator(emitter, "%TAG", 1, 0, 0))
 607                     return 0;
 608                 if (!yaml_emitter_write_tag_handle(emitter, tag_directive->handle,
 609                             strlen((char *)tag_directive->handle)))
 610                     return 0;
 611                 if (!yaml_emitter_write_tag_content(emitter, tag_directive->prefix,
 612                             strlen((char *)tag_directive->prefix), 1))
 613                     return 0;
 614                 if (!yaml_emitter_write_indent(emitter))
 615                     return 0;
 616             }
 617         }
 618
 619         if (yaml_emitter_check_empty_document(emitter)) {
 620             implicit = 0;
 621         }
 622
 623         if (!implicit) {
 624             if (!yaml_emitter_write_indent(emitter))
 625                 return 0;
 626             if (!yaml_emitter_write_indicator(emitter, "---", 1, 0, 0))
 627                 return 0;
 628             if (emitter->canonical) {
 629                 if (!yaml_emitter_write_indent(emitter))
 630                     return 0;
 631             }
 632         }
 633
 634         emitter->state = YAML_EMIT_DOCUMENT_CONTENT_STATE;
 635
 636         return 1;
 637     }
 638
 639     else if (event->type == YAML_STREAM_END_EVENT)
 640     {
 641         if (!yaml_emitter_flush(emitter))
 642             return 0;
 643
 644         emitter->state = YAML_EMIT_END_STATE;
 645
 646         return 1;
 647     }
 648
 649     return yaml_emitter_set_emitter_error(emitter,
 650             "expected DOCUMENT-START or STREAM-END");
 651 }
 652
 653 /*
 654  * Expect the root node.
 655  */
 656
 657 static int
 658 yaml_emitter_emit_document_content(yaml_emitter_t *emitter,
 659         yaml_event_t *event)
 660 {
 661     if (!PUSH(emitter, emitter->states, YAML_EMIT_DOCUMENT_END_STATE))
 662         return 0;
 663
 664     return yaml_emitter_emit_node(emitter, event, 1, 0, 0, 0);
 665 }
 666
 667 /*
 668  * Expect DOCUMENT-END.
 669  */
 670
 671 static int
 672 yaml_emitter_emit_document_end(yaml_emitter_t *emitter,
 673         yaml_event_t *event)
 674 {
 675     if (event->type == YAML_DOCUMENT_END_EVENT)
 676     {
 677         if (!yaml_emitter_write_indent(emitter))
 678             return 0;
 679         if (!event->data.document_end.implicit) {
 680             if (!yaml_emitter_write_indicator(emitter, "...", 1, 0, 0))
 681                 return 0;
 682             if (!yaml_emitter_write_indent(emitter))
 683                 return 0;
 684         }
 685         if (!yaml_emitter_flush(emitter))
 686             return 0;
 687
 688         emitter->state = YAML_EMIT_DOCUMENT_START_STATE;
 689
 690         while (!STACK_EMPTY(emitter, emitter->tag_directives)) {
 691             yaml_tag_directive_t tag_directive = POP(emitter,
 692                     emitter->tag_directives);
 693             yaml_free(tag_directive.handle);
 694             yaml_free(tag_directive.prefix);
 695         }
 696
 697         return 1;
 698     }
 699
 700     return yaml_emitter_set_emitter_error(emitter,
 701             "expected DOCUMENT-END");
 702 }
 703
 704 /*
 705  *
 706  * Expect a flow item node.
 707  */
 708
 709 static int
 710 yaml_emitter_emit_flow_sequence_item(yaml_emitter_t *emitter,
 711         yaml_event_t *event, int first)
 712 {
 713     if (first)
 714     {
 715         if (!yaml_emitter_write_indicator(emitter, "[", 1, 1, 0))
 716             return 0;
 717         if (!yaml_emitter_increase_indent(emitter, 1, 0))
 718             return 0;
 719         emitter->flow_level ++;
 720     }
 721
 722     if (event->type == YAML_SEQUENCE_END_EVENT)
 723     {
 724         emitter->flow_level --;
 725         emitter->indent = POP(emitter, emitter->indents);
 726         if (emitter->canonical && !first) {
 727             if (!yaml_emitter_write_indicator(emitter, ",", 0, 0, 0))
 728                 return 0;
 729             if (!yaml_emitter_write_indent(emitter))
 730                 return 0;
 731         }
 732         if (!yaml_emitter_write_indicator(emitter, "]", 0, 0, 0))
 733             return 0;
 734         emitter->state = POP(emitter, emitter->states);
 735
 736         return 1;
 737     }
 738
 739     if (!first) {
 740         if (!yaml_emitter_write_indicator(emitter, ",", 0, 0, 0))
 741             return 0;
 742     }
 743
 744     if (emitter->canonical || emitter->column > emitter->best_width) {
 745         if (!yaml_emitter_write_indent(emitter))
 746             return 0;
 747     }
 748     if (!PUSH(emitter, emitter->states, YAML_EMIT_FLOW_SEQUENCE_ITEM_STATE))
 749         return 0;
 750
 751     return yaml_emitter_emit_node(emitter, event, 0, 1, 0, 0);
 752 }
 753
 754 /*
 755  * Expect a flow key node.
 756  */
 757
 758 static int
 759 yaml_emitter_emit_flow_mapping_key(yaml_emitter_t *emitter,
 760         yaml_event_t *event, int first)
 761 {
 762     if (first)
 763     {
 764         if (!yaml_emitter_write_indicator(emitter, "{", 1, 1, 0))
 765             return 0;
 766         if (!yaml_emitter_increase_indent(emitter, 1, 0))
 767             return 0;
 768         emitter->flow_level ++;
 769     }
 770
 771     if (event->type == YAML_MAPPING_END_EVENT)
 772     {
 773         emitter->flow_level --;
 774         emitter->indent = POP(emitter, emitter->indents);
 775         if (emitter->canonical && !first) {
 776             if (!yaml_emitter_write_indicator(emitter, ",", 0, 0, 0))
 777                 return 0;
 778             if (!yaml_emitter_write_indent(emitter))
 779                 return 0;
 780         }
 781         if (!yaml_emitter_write_indicator(emitter, "}", 0, 0, 0))
 782             return 0;
 783         emitter->state = POP(emitter, emitter->states);
 784
 785         return 1;
 786     }
 787
 788     if (!first) {
 789         if (!yaml_emitter_write_indicator(emitter, ",", 0, 0, 0))
 790             return 0;
 791     }
 792     if (emitter->canonical || emitter->column > emitter->best_width) {
 793         if (!yaml_emitter_write_indent(emitter))
 794             return 0;
 795     }
 796
 797     if (!emitter->canonical && yaml_emitter_check_simple_key(emitter))
 798     {
 799         if (!PUSH(emitter, emitter->states,
 800                     YAML_EMIT_FLOW_MAPPING_SIMPLE_VALUE_STATE))
 801             return 0;
 802
 803         return yaml_emitter_emit_node(emitter, event, 0, 0, 1, 1);
 804     }
 805     else
 806     {
 807         if (!yaml_emitter_write_indicator(emitter, "?", 1, 0, 0))
 808             return 0;
 809         if (!PUSH(emitter, emitter->states,
 810                     YAML_EMIT_FLOW_MAPPING_VALUE_STATE))
 811             return 0;
 812
 813         return yaml_emitter_emit_node(emitter, event, 0, 0, 1, 0);
 814     }
 815 }
 816
 817 /*
 818  * Expect a flow value node.
 819  */
 820
 821 static int
 822 yaml_emitter_emit_flow_mapping_value(yaml_emitter_t *emitter,
 823         yaml_event_t *event, int simple)
 824 {
 825     if (simple) {
 826         if (!yaml_emitter_write_indicator(emitter, ":", 0, 0, 0))
 827             return 0;
 828     }
 829     else {
 830         if (emitter->canonical || emitter->column > emitter->best_width) {
 831             if (!yaml_emitter_write_indent(emitter))
 832                 return 0;
 833         }
 834         if (!yaml_emitter_write_indicator(emitter, ":", 1, 0, 0))
 835             return 0;
 836     }
 837     if (!PUSH(emitter, emitter->states, YAML_EMIT_FLOW_MAPPING_KEY_STATE))
 838         return 0;
 839     return yaml_emitter_emit_node(emitter, event, 0, 0, 1, 0);
 840 }
 841
 842 /*
 843  * Expect a block item node.
 844  */
 845
 846 static int
 847 yaml_emitter_emit_block_sequence_item(yaml_emitter_t *emitter,
 848         yaml_event_t *event, int first)
 849 {
 850     if (first)
 851     {
 852         if (!yaml_emitter_increase_indent(emitter, 0,
 853                     (emitter->mapping_context && !emitter->indention)))
 854             return 0;
 855     }
 856
 857     if (event->type == YAML_SEQUENCE_END_EVENT)
 858     {
 859         emitter->indent = POP(emitter, emitter->indents);
 860         emitter->state = POP(emitter, emitter->states);
 861
 862         return 1;
 863     }
 864
 865     if (!yaml_emitter_write_indent(emitter))
 866         return 0;
 867     if (!yaml_emitter_write_indicator(emitter, "-", 1, 0, 1))
 868         return 0;
 869     if (!PUSH(emitter, emitter->states,
 870                 YAML_EMIT_BLOCK_SEQUENCE_ITEM_STATE))
 871         return 0;
 872
 873     return yaml_emitter_emit_node(emitter, event, 0, 1, 0, 0);
 874 }
 875
 876 /*
 877  * Expect a block key node.
 878  */
 879
 880 static int
 881 yaml_emitter_emit_block_mapping_key(yaml_emitter_t *emitter,
 882         yaml_event_t *event, int first)
 883 {
 884     if (first)
 885     {
 886         if (!yaml_emitter_increase_indent(emitter, 0, 0))
 887             return 0;
 888     }
 889
 890     if (event->type == YAML_MAPPING_END_EVENT)
 891     {
 892         emitter->indent = POP(emitter, emitter->indents);
 893         emitter->state = POP(emitter, emitter->states);
 894
 895         return 1;
 896     }
 897
 898     if (!yaml_emitter_write_indent(emitter))
 899         return 0;
 900
 901     if (yaml_emitter_check_simple_key(emitter))
 902     {
 903         if (!PUSH(emitter, emitter->states,
 904                     YAML_EMIT_BLOCK_MAPPING_SIMPLE_VALUE_STATE))
 905             return 0;
 906
 907         return yaml_emitter_emit_node(emitter, event, 0, 0, 1, 1);
 908     }
 909     else
 910     {
 911         if (!yaml_emitter_write_indicator(emitter, "?", 1, 0, 1))
 912             return 0;
 913         if (!PUSH(emitter, emitter->states,
 914                     YAML_EMIT_BLOCK_MAPPING_VALUE_STATE))
 915             return 0;
 916
 917         return yaml_emitter_emit_node(emitter, event, 0, 0, 1, 0);
 918     }
 919 }
 920
 921 /*
 922  * Expect a block value node.
 923  */
 924
 925 static int
 926 yaml_emitter_emit_block_mapping_value(yaml_emitter_t *emitter,
 927         yaml_event_t *event, int simple)
 928 {
 929     if (simple) {
 930         if (!yaml_emitter_write_indicator(emitter, ":", 0, 0, 0))
 931             return 0;
 932     }
 933     else {
 934         if (!yaml_emitter_write_indent(emitter))
 935             return 0;
 936         if (!yaml_emitter_write_indicator(emitter, ":", 1, 0, 1))
 937             return 0;
 938     }
 939     if (!PUSH(emitter, emitter->states,
 940                 YAML_EMIT_BLOCK_MAPPING_KEY_STATE))
 941         return 0;
 942
 943     return yaml_emitter_emit_node(emitter, event, 0, 0, 1, 0);
 944 }
 945
 946 /*
 947  * Expect a node.
 948  */
 949
 950 static int
 951 yaml_emitter_emit_node(yaml_emitter_t *emitter, yaml_event_t *event,
 952         int root, int sequence, int mapping, int simple_key)
 953 {
 954     emitter->root_context = root;
 955     emitter->sequence_context = sequence;
 956     emitter->mapping_context = mapping;
 957     emitter->simple_key_context = simple_key;
 958
 959     switch (event->type)
 960     {
 961         case YAML_ALIAS_EVENT:
 962             return yaml_emitter_emit_alias(emitter, event);
 963
 964         case YAML_SCALAR_EVENT:
 965             return yaml_emitter_emit_scalar(emitter, event);
 966
 967         case YAML_SEQUENCE_START_EVENT:
 968             return yaml_emitter_emit_sequence_start(emitter, event);
 969
 970         case YAML_MAPPING_START_EVENT:
 971             return yaml_emitter_emit_mapping_start(emitter, event);
 972
 973         default:
 974             return yaml_emitter_set_emitter_error(emitter,
 975                     "expected SCALAR, SEQUENCE-START, MAPPING-START, or ALIAS");
 976     }
 977
 978     return 0;
 979 }
 980
 981 /*
 982  * Expect ALIAS.
 983  */
 984
 985 static int
 986 yaml_emitter_emit_alias(yaml_emitter_t *emitter, yaml_event_t *event)
 987 {
 988     if (!yaml_emitter_process_anchor(emitter))
 989         return 0;
 990     emitter->state = POP(emitter, emitter->states);
 991
 992     return 1;
 993 }
 994
 995 /*
 996  * Expect SCALAR.
 997  */
 998
 999 static int
1000 yaml_emitter_emit_scalar(yaml_emitter_t *emitter, yaml_event_t *event)
1001 {
1002     if (!yaml_emitter_select_scalar_style(emitter, event))
1003         return 0;
1004     if (!yaml_emitter_process_anchor(emitter))
1005         return 0;
1006     if (!yaml_emitter_process_tag(emitter))
1007         return 0;
1008     if (!yaml_emitter_increase_indent(emitter, 1, 0))
1009         return 0;
1010     if (!yaml_emitter_process_scalar(emitter))
1011         return 0;
1012     emitter->indent = POP(emitter, emitter->indents);
1013     emitter->state = POP(emitter, emitter->states);
1014
1015     return 1;
1016 }
1017
1018 /*
1019  * Expect SEQUENCE-START.
1020  */
1021
1022 static int
1023 yaml_emitter_emit_sequence_start(yaml_emitter_t *emitter, yaml_event_t *event)
1024 {
1025     if (!yaml_emitter_process_anchor(emitter))
1026         return 0;
1027     if (!yaml_emitter_process_tag(emitter))
1028         return 0;
1029
1030     if (emitter->flow_level || emitter->canonical
1031             || event->data.sequence_start.style == YAML_FLOW_SEQUENCE_STYLE
1032             || yaml_emitter_check_empty_sequence(emitter)) {
1033         emitter->state = YAML_EMIT_FLOW_SEQUENCE_FIRST_ITEM_STATE;
1034     }
1035     else {
1036         emitter->state = YAML_EMIT_BLOCK_SEQUENCE_FIRST_ITEM_STATE;
1037     }
1038
1039     return 1;
1040 }
1041
1042 /*
1043  * Expect MAPPING-START.
1044  */
1045
1046 static int
1047 yaml_emitter_emit_mapping_start(yaml_emitter_t *emitter, yaml_event_t *event)
1048 {
1049     if (!yaml_emitter_process_anchor(emitter))
1050         return 0;
1051     if (!yaml_emitter_process_tag(emitter))
1052         return 0;
1053
1054     if (emitter->flow_level || emitter->canonical
1055             || event->data.mapping_start.style == YAML_FLOW_MAPPING_STYLE
1056             || yaml_emitter_check_empty_mapping(emitter)) {
1057         emitter->state = YAML_EMIT_FLOW_MAPPING_FIRST_KEY_STATE;
1058     }
1059     else {
1060         emitter->state = YAML_EMIT_BLOCK_MAPPING_FIRST_KEY_STATE;
1061     }
1062
1063     return 1;
1064 }
1065
1066 /*
1067  * Check if the document content is an empty scalar.
1068  */
1069
1070 static int
1071 yaml_emitter_check_empty_document(yaml_emitter_t *emitter)
1072 {
1073     return 0;
1074 }
1075
1076 /*
1077  * Check if the next events represent an empty sequence.
1078  */
1079
1080 static int
1081 yaml_emitter_check_empty_sequence(yaml_emitter_t *emitter)
1082 {
1083     if (emitter->events.tail - emitter->events.head < 2)
1084         return 0;
1085
1086     return (emitter->events.head[0].type == YAML_SEQUENCE_START_EVENT
1087             && emitter->events.head[1].type == YAML_SEQUENCE_END_EVENT);
1088 }
1089
1090 /*
1091  * Check if the next events represent an empty mapping.
1092  */
1093
1094 static int
1095 yaml_emitter_check_empty_mapping(yaml_emitter_t *emitter)
1096 {
1097     if (emitter->events.tail - emitter->events.head < 2)
1098         return 0;
1099
1100     return (emitter->events.head[0].type == YAML_MAPPING_START_EVENT
1101             && emitter->events.head[1].type == YAML_MAPPING_END_EVENT);
1102 }
1103
1104 /*
1105  * Check if the next node can be expressed as a simple key.
1106  */
1107
1108 static int
1109 yaml_emitter_check_simple_key(yaml_emitter_t *emitter)
1110 {
1111     yaml_event_t *event = emitter->events.head;
1112     size_t length = 0;
1113
1114     switch (event->type)
1115     {
1116         case YAML_ALIAS_EVENT:
1117             length += emitter->anchor_data.anchor_length;
1118             break;
1119
1120         case YAML_SCALAR_EVENT:
1121             if (emitter->scalar_data.multiline)
1122                 return 0;
1123             length += emitter->anchor_data.anchor_length
1124                 + emitter->tag_data.handle_length
1125                 + emitter->tag_data.suffix_length
1126                 + emitter->scalar_data.length;
1127             break;
1128
1129         case YAML_SEQUENCE_START_EVENT:
1130             if (!yaml_emitter_check_empty_sequence(emitter))
1131                 return 0;
1132             length += emitter->anchor_data.anchor_length
1133                 + emitter->tag_data.handle_length
1134                 + emitter->tag_data.suffix_length;
1135             break;
1136
1137         case YAML_MAPPING_START_EVENT:
1138             if (!yaml_emitter_check_empty_sequence(emitter))
1139                 return 0;
1140             length += emitter->anchor_data.anchor_length
1141                 + emitter->tag_data.handle_length
1142                 + emitter->tag_data.suffix_length;
1143             break;
1144
1145         default:
1146             return 0;
1147     }
1148
1149     if (length > 128)
1150         return 0;
1151
1152     return 1;
1153 }
1154
1155 /*
1156  * Determine an acceptable scalar style.
1157  */
1158
1159 static int
1160 yaml_emitter_select_scalar_style(yaml_emitter_t *emitter, yaml_event_t *event)
1161 {
1162     yaml_scalar_style_t style = event->data.scalar.style;
1163     int no_tag = (!emitter->tag_data.handle && !emitter->tag_data.suffix);
1164
1165     if (no_tag && !event->data.scalar.plain_implicit
1166             && !event->data.scalar.quoted_implicit) {
1167         return yaml_emitter_set_emitter_error(emitter,
1168                 "neither tag nor implicit flags are specified");
1169     }
1170
1171     if (style == YAML_ANY_SCALAR_STYLE)
1172         style = YAML_PLAIN_SCALAR_STYLE;
1173
1174     if (emitter->canonical)
1175         style = YAML_DOUBLE_QUOTED_SCALAR_STYLE;
1176
1177     if (emitter->simple_key_context && emitter->scalar_data.multiline)
1178         style = YAML_DOUBLE_QUOTED_SCALAR_STYLE;
1179
1180     if (style == YAML_PLAIN_SCALAR_STYLE)
1181     {
1182         if ((emitter->flow_level && !emitter->scalar_data.flow_plain_allowed)
1183                 || (!emitter->flow_level && !emitter->scalar_data.block_plain_allowed))
1184             style = YAML_SINGLE_QUOTED_SCALAR_STYLE;
1185         if (!emitter->scalar_data.length
1186                 && (emitter->flow_level || emitter->simple_key_context))
1187             style = YAML_SINGLE_QUOTED_SCALAR_STYLE;
1188         if (no_tag && !event->data.scalar.plain_implicit)
1189             style = YAML_SINGLE_QUOTED_SCALAR_STYLE;
1190     }
1191
1192     if (style == YAML_SINGLE_QUOTED_SCALAR_STYLE)
1193     {
1194         if (!emitter->scalar_data.single_quoted_allowed)
1195             style = YAML_DOUBLE_QUOTED_SCALAR_STYLE;
1196     }
1197
1198     if (style == YAML_LITERAL_SCALAR_STYLE || style == YAML_FOLDED_SCALAR_STYLE)
1199     {
1200         if (!emitter->scalar_data.block_allowed
1201                 || emitter->flow_level || emitter->simple_key_context)
1202             style = YAML_DOUBLE_QUOTED_SCALAR_STYLE;
1203     }
1204
1205     if (no_tag && !event->data.scalar.quoted_implicit
1206             && style != YAML_PLAIN_SCALAR_STYLE)
1207     {
1208         emitter->tag_data.handle = (yaml_char_t *)"!";
1209         emitter->tag_data.handle_length = 1;
1210     }
1211
1212     emitter->scalar_data.style = style;
1213
1214     return 1;
1215 }
1216
1217 /*
1218  * Write an achor.
1219  */
1220
1221 static int
1222 yaml_emitter_process_anchor(yaml_emitter_t *emitter)
1223 {
1224     if (!emitter->anchor_data.anchor)
1225         return 1;
1226
1227     if (!yaml_emitter_write_indicator(emitter,
1228                 (emitter->anchor_data.alias ? "*" : "&"), 1, 0, 0))
1229         return 0;
1230
1231     return yaml_emitter_write_anchor(emitter,
1232             emitter->anchor_data.anchor, emitter->anchor_data.anchor_length);
1233 }
1234
1235 /*
1236  * Write a tag.
1237  */
1238
1239 static int
1240 yaml_emitter_process_tag(yaml_emitter_t *emitter)
1241 {
1242     if (!emitter->tag_data.handle && !emitter->tag_data.suffix)
1243         return 1;
1244
1245     if (emitter->tag_data.handle)
1246     {
1247         if (!yaml_emitter_write_tag_handle(emitter, emitter->tag_data.handle,
1248                     emitter->tag_data.handle_length))
1249             return 0;
1250         if (emitter->tag_data.suffix) {
1251             if (!yaml_emitter_write_tag_content(emitter, emitter->tag_data.suffix,
1252                         emitter->tag_data.suffix_length, 0))
1253                 return 0;
1254         }
1255     }
1256     else
1257     {
1258         if (!yaml_emitter_write_indicator(emitter, "!<", 1, 0, 0))
1259             return 0;
1260         if (!yaml_emitter_write_tag_content(emitter, emitter->tag_data.suffix,
1261                     emitter->tag_data.suffix_length, 0))
1262             return 0;
1263         if (!yaml_emitter_write_indicator(emitter, ">", 0, 0, 0))
1264             return 0;
1265     }
1266
1267     return 1;
1268 }
1269
1270 /*
1271  * Write a scalar.
1272  */
1273
1274 static int
1275 yaml_emitter_process_scalar(yaml_emitter_t *emitter)
1276 {
1277     switch (emitter->scalar_data.style)
1278     {
1279         case YAML_PLAIN_SCALAR_STYLE:
1280             return yaml_emitter_write_plain_scalar(emitter,
1281                     emitter->scalar_data.value, emitter->scalar_data.length,
1282                     !emitter->simple_key_context);
1283
1284         case YAML_SINGLE_QUOTED_SCALAR_STYLE:
1285             return yaml_emitter_write_single_quoted_scalar(emitter,
1286                     emitter->scalar_data.value, emitter->scalar_data.length,
1287                     !emitter->simple_key_context);
1288
1289         case YAML_DOUBLE_QUOTED_SCALAR_STYLE:
1290             return yaml_emitter_write_double_quoted_scalar(emitter,
1291                     emitter->scalar_data.value, emitter->scalar_data.length,
1292                     !emitter->simple_key_context);
1293
1294         case YAML_LITERAL_SCALAR_STYLE:
1295             return yaml_emitter_write_literal_scalar(emitter,
1296                     emitter->scalar_data.value, emitter->scalar_data.length);
1297
1298         case YAML_FOLDED_SCALAR_STYLE:
1299             return yaml_emitter_write_folded_scalar(emitter,
1300                     emitter->scalar_data.value, emitter->scalar_data.length);
1301
1302         default:
1303             assert(1);      /* Impossible. */
1304     }
1305
1306     return 0;
1307 }
1308
1309 /*
1310  * Check if a %YAML directive is valid.
1311  */
1312
1313 static int
1314 yaml_emitter_analyze_version_directive(yaml_emitter_t *emitter,
1315         yaml_version_directive_t version_directive)
1316 {
1317     if (version_directive.major != 1 || version_directive.minor != 1) {
1318         return yaml_emitter_set_emitter_error(emitter,
1319                 "incompatible %YAML directive");
1320     }
1321
1322     return 1;
1323 }
1324
1325 /*
1326  * Check if a %TAG directive is valid.
1327  */
1328
1329 static int
1330 yaml_emitter_analyze_tag_directive(yaml_emitter_t *emitter,
1331         yaml_tag_directive_t tag_directive)
1332 {
1333     yaml_string_t handle = STRING(tag_directive.handle,
1334             strlen((char *)tag_directive.handle));
1335     yaml_string_t prefix = STRING(tag_directive.prefix,
1336             strlen((char *)tag_directive.prefix));
1337
1338     if (handle.start == handle.end) {
1339         return yaml_emitter_set_emitter_error(emitter,
1340                 "tag handle must not be empty");
1341     }
1342
1343     if (handle.start[0] != '!') {
1344         return yaml_emitter_set_emitter_error(emitter,
1345                 "tag handle must start with '!'");
1346     }
1347
1348     if (handle.end[-1] != '!') {
1349         return yaml_emitter_set_emitter_error(emitter,
1350                 "tag handle must end with '!'");
1351     }
1352
1353     handle.pointer ++;
1354
1355     while (handle.pointer < handle.end-1) {
1356         if (!IS_ALPHA(handle)) {
1357             return yaml_emitter_set_emitter_error(emitter,
1358                     "tag handle must contain alphanumerical characters only");
1359         }
1360         MOVE(handle);
1361     }
1362
1363     if (prefix.start == prefix.end) {
1364         return yaml_emitter_set_emitter_error(emitter,
1365                 "tag prefix must not be empty");
1366     }
1367
1368     return 1;
1369 }
1370
1371 /*
1372  * Check if an anchor is valid.
1373  */
1374
1375 static int
1376 yaml_emitter_analyze_anchor(yaml_emitter_t *emitter,
1377         yaml_char_t *anchor, int alias)
1378 {
1379     yaml_string_t string = STRING(anchor, strlen((char *)anchor));
1380
1381     if (string.start == string.end) {
1382         return yaml_emitter_set_emitter_error(emitter, alias ?
1383                 "alias value must not be empty" :
1384                 "anchor value must not be empty");
1385     }
1386
1387     while (string.pointer != string.end) {
1388         if (!IS_ALPHA(string)) {
1389             return yaml_emitter_set_emitter_error(emitter, alias ?
1390                     "alias value must contain alphanumerical characters only" :
1391                     "anchor value must contain alphanumerical characters only");
1392         }
1393         MOVE(string);
1394     }
1395
1396     emitter->anchor_data.anchor = string.start;
1397     emitter->anchor_data.anchor_length = string.end - string.start;
1398     emitter->anchor_data.alias = alias;
1399
1400     return 1;
1401 }
1402
1403 /*
1404  * Check if a tag is valid.
1405  */
1406
1407 static int
1408 yaml_emitter_analyze_tag(yaml_emitter_t *emitter,
1409         yaml_char_t *tag)
1410 {
1411     yaml_string_t string = STRING(tag, strlen((char *)tag));
1412     yaml_tag_directive_t *tag_directive;
1413
1414     if (string.start == string.end) {
1415         return yaml_emitter_set_emitter_error(emitter,
1416                 "tag value must not be empty");
1417     }
1418
1419     for (tag_directive = emitter->tag_directives.start;
1420             tag_directive != emitter->tag_directives.top; tag_directive ++) {
1421         size_t prefix_length = strlen((char *)tag_directive->prefix);
1422         if (prefix_length < (size_t)(string.end - string.start)
1423                 && strncmp((char *)tag_directive->prefix, (char *)string.start,
1424                     prefix_length) == 0)
1425         {
1426             emitter->tag_data.handle = tag_directive->handle;
1427             emitter->tag_data.handle_length =
1428                 strlen((char *)tag_directive->handle);
1429             emitter->tag_data.suffix = string.start + prefix_length;
1430             emitter->tag_data.suffix_length =
1431                 (string.end - string.start) - prefix_length;
1432             return 1;
1433         }
1434     }
1435
1436     emitter->tag_data.suffix = string.start;
1437     emitter->tag_data.suffix_length = string.end - string.start;
1438
1439     return 1;
1440 }
1441
1442 /*
1443  * Check if a scalar is valid.
1444  */
1445
1446 static int
1447 yaml_emitter_analyze_scalar(yaml_emitter_t *emitter,
1448         yaml_char_t *value, size_t length)
1449 {
1450     yaml_string_t string = STRING(value, length);
1451
1452     int block_indicators = 0;
1453     int flow_indicators = 0;
1454     int line_breaks = 0;
1455     int special_characters = 0;
1456
1457     int inline_spaces = 0;
1458     int inline_breaks = 0;
1459     int leading_spaces = 0;
1460     int leading_breaks = 0;
1461     int trailing_spaces = 0;
1462     int trailing_breaks = 0;
1463     int inline_breaks_spaces = 0;
1464     int mixed_breaks_spaces = 0;
1465
1466     int preceeded_by_space = 0;
1467     int followed_by_space = 0;
1468     int spaces = 0;
1469     int breaks = 0;
1470     int mixed = 0;
1471     int leading = 0;
1472
1473     emitter->scalar_data.value = value;
1474     emitter->scalar_data.length = length;
1475
1476     if (string.start == string.end)
1477     {
1478         emitter->scalar_data.multiline = 0;
1479         emitter->scalar_data.flow_plain_allowed = 0;
1480         emitter->scalar_data.block_plain_allowed = 1;
1481         emitter->scalar_data.single_quoted_allowed = 1;
1482         emitter->scalar_data.block_allowed = 0;
1483
1484         return 1;
1485     }
1486
1487     if ((CHECK_AT(string, '-', 0)
1488                 && CHECK_AT(string, '-', 1)
1489                 && CHECK_AT(string, '-', 2))
1490             || (CHECK_AT(string, '.', 0)
1491                 && CHECK_AT(string, '.', 1)
1492                 && CHECK_AT(string, '.', 2))) {
1493         block_indicators = 1;
1494         flow_indicators = 1;
1495     }
1496
1497     preceeded_by_space = 1;
1498     followed_by_space = IS_BLANKZ_AT(string, WIDTH(string));
1499
1500     while (string.pointer != string.end)
1501     {
1502         if (string.start == string.pointer)
1503         {
1504             if (CHECK(string, '#') || CHECK(string, ',')
1505                     || CHECK(string, '[') || CHECK(string, ']')
1506                     || CHECK(string, '{') || CHECK(string, '}')
1507                     || CHECK(string, '&') || CHECK(string, '*')
1508                     || CHECK(string, '!') || CHECK(string, '|')
1509                     || CHECK(string, '>') || CHECK(string, '\'')
1510                     || CHECK(string, '"') || CHECK(string, '%')
1511                     || CHECK(string, '@') || CHECK(string, '`')) {
1512                 flow_indicators = 1;
1513                 block_indicators = 1;
1514             }
1515
1516             if (CHECK(string, '?') || CHECK(string, ':')) {
1517                 flow_indicators = 1;
1518                 if (followed_by_space) {
1519                     block_indicators = 1;
1520                 }
1521             }
1522
1523             if (CHECK(string, '-') && followed_by_space) {
1524                 flow_indicators = 1;
1525                 block_indicators = 1;
1526             }
1527         }
1528         else
1529         {
1530             if (CHECK(string, ',') || CHECK(string, '?')
1531                     || CHECK(string, '[') || CHECK(string, ']')
1532                     || CHECK(string, '{') || CHECK(string, '}')) {
1533                 flow_indicators = 1;
1534             }
1535
1536             if (CHECK(string, ':')) {
1537                 flow_indicators = 1;
1538                 if (followed_by_space) {
1539                     block_indicators = 1;
1540                 }
1541             }
1542
1543             if (CHECK(string, '#') && preceeded_by_space) {
1544                 flow_indicators = 1;
1545                 block_indicators = 1;
1546             }
1547         }
1548
1549         if (!IS_PRINTABLE(string)
1550                 || (!IS_ASCII(string) && !emitter->unicode)) {
1551             special_characters = 1;
1552         }
1553
1554         if (IS_BREAK(string)) {
1555             line_breaks = 1;
1556         }
1557
1558         if (IS_SPACE(string))
1559         {
1560             spaces = 1;
1561             if (string.start == string.pointer) {
1562                 leading = 1;
1563             }
1564         }
1565
1566         else if (IS_BREAK(string))
1567         {
1568             if (spaces) {
1569                 mixed = 1;
1570             }
1571             breaks = 1;
1572             if (string.start == string.pointer) {
1573                 leading = 1;
1574             }
1575         }
1576
1577         else if (spaces || breaks)
1578         {
1579             if (leading) {
1580                 if (spaces && breaks) {
1581                     mixed_breaks_spaces = 1;
1582                 }
1583                 else if (spaces) {
1584                     leading_spaces = 1;
1585                 }
1586                 else if (breaks) {
1587                     leading_breaks = 1;
1588                 }
1589             }
1590             else {
1591                 if (mixed) {
1592                     mixed_breaks_spaces = 1;
1593                 }
1594                 else if (spaces && breaks) {
1595                     inline_breaks_spaces = 1;
1596                 }
1597                 else if (spaces) {
1598                     inline_spaces = 1;
1599                 }
1600                 else if (breaks) {
1601                     inline_breaks = 1;
1602                 }
1603             }
1604             spaces = breaks = mixed = leading = 0;
1605         }
1606
1607         if ((spaces || breaks) && string.pointer == string.end-1)
1608         {
1609             if (spaces && breaks) {
1610                 mixed_breaks_spaces = 1;
1611             }
1612             else if (spaces) {
1613                 if (leading) {
1614                     leading_spaces = 1;
1615                 }
1616                 trailing_spaces = 1;
1617             }
1618             else if (breaks) {
1619                 if (leading) {
1620                     leading_breaks = 1;
1621                 }
1622                 trailing_breaks = 1;
1623             }
1624         }
1625
1626         preceeded_by_space = IS_BLANKZ(string);
1627         MOVE(string);
1628         if (string.pointer != string.end) {
1629             followed_by_space = IS_BLANKZ_AT(string, WIDTH(string));
1630         }
1631     }
1632
1633     emitter->scalar_data.multiline = line_breaks;
1634
1635     emitter->scalar_data.flow_plain_allowed = 1;
1636     emitter->scalar_data.block_plain_allowed = 1;
1637     emitter->scalar_data.single_quoted_allowed = 1;
1638     emitter->scalar_data.block_allowed = 1;
1639
1640     if (leading_spaces || leading_breaks || trailing_spaces) {
1641         emitter->scalar_data.flow_plain_allowed = 0;
1642         emitter->scalar_data.block_plain_allowed = 0;
1643         emitter->scalar_data.block_allowed = 0;
1644     }
1645
1646     if (trailing_breaks) {
1647         emitter->scalar_data.flow_plain_allowed = 0;
1648         emitter->scalar_data.block_plain_allowed = 0;
1649     }
1650
1651     if (inline_breaks_spaces) {
1652         emitter->scalar_data.flow_plain_allowed = 0;
1653         emitter->scalar_data.block_plain_allowed = 0;
1654         emitter->scalar_data.single_quoted_allowed = 0;
1655     }
1656
1657     if (mixed_breaks_spaces || special_characters) {
1658         emitter->scalar_data.flow_plain_allowed = 0;
1659         emitter->scalar_data.block_plain_allowed = 0;
1660         emitter->scalar_data.single_quoted_allowed = 0;
1661         emitter->scalar_data.block_allowed = 0;
1662     }
1663
1664     if (line_breaks) {
1665         emitter->scalar_data.flow_plain_allowed = 0;
1666         emitter->scalar_data.block_plain_allowed = 0;
1667     }
1668
1669     if (flow_indicators) {
1670         emitter->scalar_data.flow_plain_allowed = 0;
1671     }
1672
1673     if (block_indicators) {
1674         emitter->scalar_data.block_plain_allowed = 0;
1675     }
1676
1677     return 1;
1678 }
1679
1680 /*
1681  * Check if the event data is valid.
1682  */
1683
1684 static int
1685 yaml_emitter_analyze_event(yaml_emitter_t *emitter,
1686         yaml_event_t *event)
1687 {
1688     emitter->anchor_data.anchor = NULL;
1689     emitter->anchor_data.anchor_length = 0;
1690     emitter->tag_data.handle = NULL;
1691     emitter->tag_data.handle_length = 0;
1692     emitter->tag_data.suffix = NULL;
1693     emitter->tag_data.suffix_length = 0;
1694     emitter->scalar_data.value = NULL;
1695     emitter->scalar_data.length = 0;
1696
1697     switch (event->type)
1698     {
1699         case YAML_ALIAS_EVENT:
1700             if (!yaml_emitter_analyze_anchor(emitter,
1701                         event->data.alias.anchor, 1))
1702                 return 0;
1703             return 1;
1704
1705         case YAML_SCALAR_EVENT:
1706             if (event->data.scalar.anchor) {
1707                 if (!yaml_emitter_analyze_anchor(emitter,
1708                             event->data.scalar.anchor, 0))
1709                     return 0;
1710             }
1711             if (event->data.scalar.tag && (emitter->canonical ||
1712                         (!event->data.scalar.plain_implicit
1713                          && !event->data.scalar.quoted_implicit))) {
1714                 if (!yaml_emitter_analyze_tag(emitter, event->data.scalar.tag))
1715                     return 0;
1716             }
1717             if (!yaml_emitter_analyze_scalar(emitter,
1718                         event->data.scalar.value, event->data.scalar.length))
1719                 return 0;
1720             return 1;
1721
1722         case YAML_SEQUENCE_START_EVENT:
1723             if (event->data.sequence_start.anchor) {
1724                 if (!yaml_emitter_analyze_anchor(emitter,
1725                             event->data.sequence_start.anchor, 0))
1726                     return 0;
1727             }
1728             if (event->data.sequence_start.tag && (emitter->canonical ||
1729                         !event->data.sequence_start.implicit)) {
1730                 if (!yaml_emitter_analyze_tag(emitter,
1731                             event->data.sequence_start.tag))
1732                     return 0;
1733             }
1734             return 1;
1735
1736         case YAML_MAPPING_START_EVENT:
1737             if (event->data.mapping_start.anchor) {
1738                 if (!yaml_emitter_analyze_anchor(emitter,
1739                             event->data.mapping_start.anchor, 0))
1740                     return 0;
1741             }
1742             if (event->data.mapping_start.tag && (emitter->canonical ||
1743                         !event->data.mapping_start.implicit)) {
1744                 if (!yaml_emitter_analyze_tag(emitter,
1745                             event->data.mapping_start.tag))
1746                     return 0;
1747             }
1748             return 1;
1749
1750         default:
1751             return 1;
1752     }
1753 }
1754
1755 /*
1756  * Write the BOM character.
1757  */
1758
1759 static int
1760 yaml_emitter_write_bom(yaml_emitter_t *emitter)
1761 {
1762     if (!FLUSH(emitter)) return 0;
1763
1764     *(emitter->buffer.pointer++) = (yaml_char_t) '\xEF';
1765     *(emitter->buffer.pointer++) = (yaml_char_t) '\xBB';
1766     *(emitter->buffer.pointer++) = (yaml_char_t) '\xBF';
1767
1768     return 1;
1769 }
1770
1771 static int
1772 yaml_emitter_write_indent(yaml_emitter_t *emitter)
1773 {
1774     int indent = (emitter->indent >= 0) ? emitter->indent : 0;
1775
1776     if (!emitter->indention || emitter->column > indent
1777             || (emitter->column == indent && !emitter->whitespace)) {
1778         if (!PUT_BREAK(emitter)) return 0;
1779     }
1780
1781     while (emitter->column < indent) {
1782         if (!PUT(emitter, ' ')) return 0;
1783     }
1784
1785     emitter->whitespace = 1;
1786     emitter->indention = 1;
1787
1788     return 1;
1789 }
1790
1791 static int
1792 yaml_emitter_write_indicator(yaml_emitter_t *emitter,
1793         char *indicator, int need_whitespace,
1794         int is_whitespace, int is_indention)
1795 {
1796     yaml_string_t string = STRING((yaml_char_t *)indicator, strlen(indicator));
1797
1798     if (need_whitespace && !emitter->whitespace) {
1799         if (!PUT(emitter, ' ')) return 0;
1800     }
1801
1802     while (string.pointer != string.end) {
1803         if (!WRITE(emitter, string)) return 0;
1804     }
1805
1806     emitter->whitespace = is_whitespace;
1807     emitter->indention = (emitter->indention && is_indention);
1808
1809     return 1;
1810 }
1811
1812 static int
1813 yaml_emitter_write_anchor(yaml_emitter_t *emitter,
1814         yaml_char_t *value, size_t length)
1815 {
1816     yaml_string_t string = STRING(value, length);
1817
1818     while (string.pointer != string.end) {
1819         if (!WRITE(emitter, string)) return 0;
1820     }
1821
1822     emitter->whitespace = 0;
1823     emitter->indention = 0;
1824
1825     return 1;
1826 }
1827
1828 static int
1829 yaml_emitter_write_tag_handle(yaml_emitter_t *emitter,
1830         yaml_char_t *value, size_t length)
1831 {
1832     yaml_string_t string = STRING(value, length);
1833
1834     if (!emitter->whitespace) {
1835         if (!PUT(emitter, ' ')) return 0;
1836     }
1837
1838     while (string.pointer != string.end) {
1839         if (!WRITE(emitter, string)) return 0;
1840     }
1841
1842     emitter->whitespace = 0;
1843     emitter->indention = 0;
1844
1845     return 1;
1846 }
1847
1848 static int
1849 yaml_emitter_write_tag_content(yaml_emitter_t *emitter,
1850         yaml_char_t *value, size_t length,
1851         int need_whitespace)
1852 {
1853     yaml_string_t string = STRING(value, length);
1854
1855     if (need_whitespace && !emitter->whitespace) {
1856         if (!PUT(emitter, ' ')) return 0;
1857     }
1858
1859     while (string.pointer != string.end) {
1860         if (IS_ALPHA(string)
1861                 || CHECK(string, ';') || CHECK(string, '/')
1862                 || CHECK(string, '?') || CHECK(string, ':')
1863                 || CHECK(string, '@') || CHECK(string, '&')
1864                 || CHECK(string, '=') || CHECK(string, '+')
1865                 || CHECK(string, '$') || CHECK(string, ',')
1866                 || CHECK(string, '_') || CHECK(string, '.')
1867                 || CHECK(string, '~') || CHECK(string, '*')
1868                 || CHECK(string, '\'') || CHECK(string, '(')
1869                 || CHECK(string, ')') || CHECK(string, '[')
1870                 || CHECK(string, ']')) {
1871             if (!WRITE(emitter, string)) return 0;
1872         }
1873         else {
1874             int width = WIDTH(string);
1875             unsigned int value;
1876             while (width --) {
1877                 value = *(string.pointer++);
1878                 if (!PUT(emitter, '%')) return 0;
1879                 if (!PUT(emitter, (value >> 4)
1880                             + ((value >> 4) < 10 ? '0' : 'A' - 10)))
1881                     return 0;
1882                 if (!PUT(emitter, (value & 0x0F)
1883                             + ((value & 0x0F) < 10 ? '0' : 'A' - 10)))
1884                     return 0;
1885             }
1886         }
1887     }
1888
1889     emitter->whitespace = 0;
1890     emitter->indention = 0;
1891
1892     return 1;
1893 }
1894
1895 static int
1896 yaml_emitter_write_plain_scalar(yaml_emitter_t *emitter,
1897         yaml_char_t *value, size_t length, int allow_breaks)
1898 {
1899     yaml_string_t string = STRING(value, length);
1900     int spaces = 0;
1901     int breaks = 0;
1902
1903     if (!emitter->whitespace) {
1904         if (!PUT(emitter, ' ')) return 0;
1905     }
1906
1907     while (string.pointer != string.end)
1908     {
1909         if (IS_SPACE(string))
1910         {
1911             if (allow_breaks && !spaces
1912                     && emitter->column > emitter->best_width
1913                     && !IS_SPACE_AT(string, 1)) {
1914                 if (!yaml_emitter_write_indent(emitter)) return 0;
1915                 MOVE(string);
1916             }
1917             else {
1918                 if (!WRITE(emitter, string)) return 0;
1919             }
1920             spaces = 1;
1921         }
1922         else if (IS_BREAK(string))
1923         {
1924             if (!breaks && CHECK(string, '\n')) {
1925                 if (!PUT_BREAK(emitter)) return 0;
1926             }
1927             if (!WRITE_BREAK(emitter, string)) return 0;
1928             emitter->indention = 1;
1929             breaks = 1;
1930         }
1931         else
1932         {
1933             if (breaks) {
1934                 if (!yaml_emitter_write_indent(emitter)) return 0;
1935             }
1936             if (!WRITE(emitter, string)) return 0;
1937             emitter->indention = 0;
1938             spaces = 0;
1939             breaks = 0;
1940         }
1941     }
1942
1943     emitter->whitespace = 0;
1944     emitter->indention = 0;
1945
1946     return 1;
1947 }
1948
1949 static int
1950 yaml_emitter_write_single_quoted_scalar(yaml_emitter_t *emitter,
1951         yaml_char_t *value, size_t length, int allow_breaks)
1952 {
1953     yaml_string_t string = STRING(value, length);
1954     int spaces = 0;
1955     int breaks = 0;
1956
1957     if (!yaml_emitter_write_indicator(emitter, "'", 1, 0, 0))
1958         return 0;
1959
1960     while (string.pointer != string.end)
1961     {
1962         if (IS_SPACE(string))
1963         {
1964             if (allow_breaks && !spaces
1965                     && emitter->column > emitter->best_width
1966                     && string.pointer != string.start
1967                     && string.pointer != string.end - 1
1968                     && !IS_SPACE_AT(string, 1)) {
1969                 if (!yaml_emitter_write_indent(emitter)) return 0;
1970                 MOVE(string);
1971             }
1972             else {
1973                 if (!WRITE(emitter, string)) return 0;
1974             }
1975             spaces = 1;
1976         }
1977         else if (IS_BREAK(string))
1978         {
1979             if (!breaks && CHECK(string, '\n')) {
1980                 if (!PUT_BREAK(emitter)) return 0;
1981             }
1982             if (!WRITE_BREAK(emitter, string)) return 0;
1983             emitter->indention = 1;
1984             breaks = 1;
1985         }
1986         else
1987         {
1988             if (breaks) {
1989                 if (!yaml_emitter_write_indent(emitter)) return 0;
1990             }
1991             if (CHECK(string, '\'')) {
1992                 if (!PUT(emitter, '\'')) return 0;
1993             }
1994             if (!WRITE(emitter, string)) return 0;
1995             emitter->indention = 0;
1996             spaces = 0;
1997             breaks = 0;
1998         }
1999     }
2000
2001     if (!yaml_emitter_write_indicator(emitter, "'", 0, 0, 0))
2002         return 0;
2003
2004     emitter->whitespace = 0;
2005     emitter->indention = 0;
2006
2007     return 1;
2008 }
2009
2010 static int
2011 yaml_emitter_write_double_quoted_scalar(yaml_emitter_t *emitter,
2012         yaml_char_t *value, size_t length, int allow_breaks)
2013 {
2014     yaml_string_t string = STRING(value, length);
2015     int spaces = 0;
2016
2017     if (!yaml_emitter_write_indicator(emitter, "\"", 1, 0, 0))
2018         return 0;
2019
2020     while (string.pointer != string.end)
2021     {
2022         if (!IS_PRINTABLE(string) || (!emitter->unicode && !IS_ASCII(string))
2023                 || IS_BOM(string) || IS_BREAK(string)
2024                 || CHECK(string, '"') || CHECK(string, '\\'))
2025         {
2026             unsigned char octet;
2027             unsigned int width;
2028             unsigned int value;
2029             size_t k;
2030
2031             octet = string.pointer[0];
2032             width = (octet & 0x80) == 0x00 ? 1 :
2033                     (octet & 0xE0) == 0xC0 ? 2 :
2034                     (octet & 0xF0) == 0xE0 ? 3 :
2035                     (octet & 0xF8) == 0xF0 ? 4 : 0;
2036             value = (octet & 0x80) == 0x00 ? octet & 0x7F :
2037                     (octet & 0xE0) == 0xC0 ? octet & 0x1F :
2038                     (octet & 0xF0) == 0xE0 ? octet & 0x0F :
2039                     (octet & 0xF8) == 0xF0 ? octet & 0x07 : 0;
2040             for (k = 1; k < width; k ++) {
2041                 octet = string.pointer[k];
2042                 value = (value << 6) + (octet & 0x3F);
2043             }
2044             string.pointer += width;
2045
2046             if (!PUT(emitter, '\\')) return 0;
2047
2048             switch (value)
2049             {
2050                 case 0x00:
2051                     if (!PUT(emitter, '0')) return 0;
2052                     break;
2053
2054                 case 0x07:
2055                     if (!PUT(emitter, 'a')) return 0;
2056                     break;
2057
2058                 case 0x08:
2059                     if (!PUT(emitter, 'b')) return 0;
2060                     break;
2061
2062                 case 0x09:
2063                     if (!PUT(emitter, 't')) return 0;
2064                     break;
2065
2066                 case 0x0A:
2067                     if (!PUT(emitter, 'n')) return 0;
2068                     break;
2069
2070                 case 0x0B:
2071                     if (!PUT(emitter, 'v')) return 0;
2072                     break;
2073
2074                 case 0x0C:
2075                     if (!PUT(emitter, 'f')) return 0;
2076                     break;
2077
2078                 case 0x0D:
2079                     if (!PUT(emitter, 'r')) return 0;
2080                     break;
2081
2082                 case 0x1B:
2083                     if (!PUT(emitter, 'e')) return 0;
2084                     break;
2085
2086                 case 0x22:
2087                     if (!PUT(emitter, '\"')) return 0;
2088                     break;
2089
2090                 case 0x5C:
2091                     if (!PUT(emitter, '\\')) return 0;
2092                     break;
2093
2094                 case 0x85:
2095                     if (!PUT(emitter, 'N')) return 0;
2096                     break;
2097
2098                 case 0xA0:
2099                     if (!PUT(emitter, '_')) return 0;
2100                     break;
2101
2102                 case 0x2028:
2103                     if (!PUT(emitter, 'L')) return 0;
2104                     break;
2105
2106                 case 0x2029:
2107                     if (!PUT(emitter, 'P')) return 0;
2108                     break;
2109
2110                 default:
2111                     if (value <= 0xFF) {
2112                         if (!PUT(emitter, 'x')) return 0;
2113                         width = 2;
2114                     }
2115                     else if (value <= 0xFFFF) {
2116                         if (!PUT(emitter, 'u')) return 0;
2117                         width = 4;
2118                     }
2119                     else {
2120                         if (!PUT(emitter, 'U')) return 0;
2121                         width = 8;
2122                     }
2123                     for (k = (width-1)*4; k >= 0; k -= 4) {
2124                         int digit = (value >> k) & 0x0F;
2125                         if (!PUT(emitter, digit + (digit < 10 ? '0' : 'A'-10)))
2126                             return 0;
2127                     }
2128             }
2129             spaces = 0;
2130         }
2131         else if (IS_SPACE(string))
2132         {
2133             if (allow_breaks && !spaces
2134                     && emitter->column > emitter->best_width
2135                     && string.pointer != string.start
2136                     && string.pointer != string.end - 1) {
2137                 if (!yaml_emitter_write_indent(emitter)) return 0;
2138                 if (IS_SPACE_AT(string, 1)) {
2139                     if (!PUT(emitter, '\\')) return 0;
2140                 }
2141                 MOVE(string);
2142             }
2143             else {
2144                 if (!WRITE(emitter, string)) return 0;
2145             }
2146             spaces = 1;
2147         }
2148         else
2149         {
2150             if (!WRITE(emitter, string)) return 0;
2151             spaces = 0;
2152         }
2153     }
2154
2155     if (!yaml_emitter_write_indicator(emitter, "\"", 0, 0, 0))
2156         return 0;
2157
2158     emitter->whitespace = 0;
2159     emitter->indention = 0;
2160
2161     return 1;
2162 }
2163
2164 static int
2165 yaml_emitter_determine_chomping(yaml_emitter_t *emitter,
2166         yaml_string_t string)
2167 {
2168     string.pointer = string.end;
2169     if (string.start == string.pointer)
2170         return -1;
2171     do {
2172         string.pointer --;
2173     } while ((*string.pointer & 0xC0) == 0x80);
2174     if (!IS_BREAK(string))
2175         return -1;
2176     if (string.start == string.pointer)
2177         return 0;
2178     do {
2179         string.pointer --;
2180     } while ((*string.pointer & 0xC0) == 0x80);
2181     if (!IS_BREAK(string))
2182         return 0;
2183     return +1;
2184
2185 }
2186
2187 static int
2188 yaml_emitter_write_literal_scalar(yaml_emitter_t *emitter,
2189         yaml_char_t *value, size_t length)
2190 {
2191     yaml_string_t string = STRING(value, length);
2192     int chomp = yaml_emitter_determine_chomping(emitter, string);
2193     int breaks = 0;
2194
2195     if (!yaml_emitter_write_indicator(emitter,
2196                 chomp == -1 ? "|-" : chomp == +1 ? "|+" : "|", 1, 0, 0))
2197         return 0;
2198     if (!yaml_emitter_write_indent(emitter))
2199         return 0;
2200
2201     while (string.pointer != string.end)
2202     {
2203         if (IS_BREAK(string))
2204         {
2205             if (!WRITE_BREAK(emitter, string)) return 0;
2206             emitter->indention = 1;
2207             breaks = 1;
2208         }
2209         else
2210         {
2211             if (breaks) {
2212                 if (!yaml_emitter_write_indent(emitter)) return 0;
2213             }
2214             if (!WRITE(emitter, string)) return 0;
2215             emitter->indention = 0;
2216             breaks = 0;
2217         }
2218     }
2219
2220     return 1;
2221 }
2222
2223 static int
2224 yaml_emitter_write_folded_scalar(yaml_emitter_t *emitter,
2225         yaml_char_t *value, size_t length)
2226 {
2227     yaml_string_t string = STRING(value, length);
2228     int chomp = yaml_emitter_determine_chomping(emitter, string);
2229     int breaks = 1;
2230     int leading_spaces = 0;
2231
2232     if (!yaml_emitter_write_indicator(emitter,
2233                 chomp == -1 ? ">-" : chomp == +1 ? ">+" : ">", 1, 0, 0))
2234         return 0;
2235     if (!yaml_emitter_write_indent(emitter))
2236         return 0;
2237
2238     while (string.pointer != string.end)
2239     {
2240         if (IS_BREAK(string))
2241         {
2242             if (!breaks && !leading_spaces && CHECK(string, '\n')) {
2243                 int k = 0;
2244                 while (IS_BREAK_AT(string, k)) {
2245                     k += WIDTH_AT(string, k);
2246                 }
2247                 if (!IS_BLANK_AT(string, k)) {
2248                     if (!PUT_BREAK(emitter)) return 0;
2249                 }
2250             }
2251             if (!WRITE_BREAK(emitter, string)) return 0;
2252             emitter->indention = 1;
2253             breaks = 1;
2254         }
2255         else
2256         {
2257             if (breaks) {
2258                 if (!yaml_emitter_write_indent(emitter)) return 0;
2259                 leading_spaces = IS_BLANK(string);
2260             }
2261             if (!breaks && IS_SPACE(string) && !IS_SPACE_AT(string, 1)
2262                     && emitter->column > emitter->best_width) {
2263                 if (!yaml_emitter_write_indent(emitter)) return 0;
2264                 MOVE(string);
2265             }
2266             else {
2267                 if (!WRITE(emitter, string)) return 0;
2268             }
2269             emitter->indention = 0;
2270             breaks = 0;
2271         }
2272     }
2273
2274     return 1;
2275 }
2276